Extension-ladder.



A. P. BUYER.

EXTENSION LADDER.

APPLICATION FILED APR. 20, 1911.

Patented Apr. 22, 1913.

9; linzaowo ALLEN nanorznnyor eosumv, INDIANA.1

1 EXTENSION-LADDER:

Specification ofletters Patent. 1

1 Application fi1ed Apr i1120,19111. Seria1 N0.622,242. 1

To all aroma mayconcem: p Beiit known that I, ALLEN :P. Borne, a

citizen of thehUnited 1States, residing;yat, Goshen, Indianayhave invented certainnew and useful Improvements in 1 Extension-p Ladders, of which the following is a specifi-i cation. 1

This invention relates to improvements in extension 1 ladders. 1

The objects of this invention are to pro-1 1 vide an automatic locking dev ce for exten-:

sion ladders, which is simple in structure and of such a character as toinsure com-1 plete and efi'ective automatic operation. 1

Further objects relatingjto economies of construction, and details of operation, will definitely appear'from ithe 1 description ltO follow I 1 1 1 I accomplishlthe objects of invention bythe devices and means descrlbed in the following specification;

The invent1on; 1sclearly defined and pointed 1 out in the :claims. 1

A structure showing a preferred embodi-i ment of my invention is 1clearly illustrated in the accompanying drawing; forming a part of this specification,1in1which 1 Figure Iis a detail elevation view of the parts of an extension ladder necessary ;to

understand myimprovements. Fig. IIis a I detail sectional elevation on line 2+2 of Fig.; 1, showing; the ladder in inclined} position. Fig. III is an enlargedtransverselsectional;

view, taken on aline corresponding to line 3--3 of Fig.1 I,lshowing a detail of the guide 1 brackets. M Fig. IVis 1a detailsectional view on thecurved line 4-4 of Fig; II, showing the guidinglmeans. 1 1

In the drawing, the sectional lviews are taken looking in the direction of ithe little? arrows at the ends of the section linesyand similar numerals of reference refer to sirhi? lar parts throughout the SGVGI'illi views; 1

Referring to the numbered parts 10f ithe drawing, the lower section 110f the ladder carries the upper or: extension. section 2,

which rests upon 1- the rungsi B 1thereof,and 1 is retained in placeby; guide brackets 4 4,

which clearly appear in Figs. Iand III,1asmany brackets 41: being provided as are necessary to eflicientl 1 guide thexupper \orextension section.

11* the "upper 1 or 1 extension 1 section; I provide the automatic locking member 5, pivoting, the same at 6 with a 1 suitable curved retainer 7 to ettectivelykeep Patented Apr. 22,112,134: 1

the same in place, the lower end 9 of which 1 serves as the guide for the lock. The hook 1 is provided with a guidingcross bar 8 cm gaged by theguide 9 above mentioned. The 1 lock1is provided with a downwardly-engage mg fin er 10, which engages over the rung of the ottom section of the ladderto lock the extensionwin elevated (position, and is I provided 1 with a 1 downwardlyprojectinlg j hook finger ill, which embraces the rung 3 of the upper or extension section 2,1and has 1 anenlarged head portion 1 12:at the end to 1 be acted uponby the trip device. 1

The trip; device 13 is pivoted at 14:, and 1 has a retainer. 15 to protect the same and retalnl t in place, and to serve as a stopto limit its movement and insure itsremaining in operative position. A fingeror arm of the trip, 16, projectsinv proximity to the head end 12 of the hookifinger 11,to\act1 HPOIllthB same, and a weight 17 lisoppositew the same which normallydepends downward and brings the tip into operative position! Afinger :18 from the trip deyiceextends, owing to the action ofthe weight 17,1normally beyond the back edge of the side rail, 1 of the upper or extension section, so that it 1 will be contacted and ?acted upon by; the 1 rungs 3 ofthe bottom section whenfthe 1extension section is moved up and down in passage; It will be seen that in manipu1ation, the upper or extension section can be 1 readily raised to any height desired, and by stopping the same when the lock fingerlO has dropped past one of the rungs 3 of the the same.

and extends above any rung 3 ofthe bottom section, when the. extension section: is

lowered,: this ifinger acts as a lever and guard and when it comes in contact with the: rungaof the lower section asit. descends,

throws the lever 16, acts on the hook at 12 1 and raises up; until the lever 18 comes in contact with the hook finger at 10and thus prevents the locking process by means of the 1 double action, owing to the fact that; the 1 finger 18 swings upwardly against the hook 1 bottom section,1the lock will readily engage 1 Whereas, if the extension [sec- 1 tion is raised so that the finger l8 1passes lowered .to any point, desireda When the finger guard "18 is acted on by the loweringj of the upper sectionso that the rungs .ofthe V embraces the rung'of the upper or extension lower section raise the same, the finger 16 first acts and partially throws the IOCkfSQw "that when the finger 18 strikes'tlie 1001;

finger it is already partially depressed and very'easily engaged and operated, by a jeotionable long fingers: to bend and break. The upper or extension section is manipucomparatively short finger-f: I am able to use tected bythe rails ofthekladder. The device is thus very-compact without any-obs lated by hand,,or' by any suitable means not, necessary to illustrate I 7 I have shown myimproved structure with a 1weight17 for holding the tripmember normally in the required position; and this is the-preferred construction, but it will be readily understoodthat asimilar trip can be provided with other-means forjretaining it normally in the operative position. .I have shown the'prefe'rred form;

My improved lock can also be ,manipu: lated by other devices and; it will be "found to be very effective because it completely and effectively locks the .upperior extension secs ,tionto: the a-main sectionby embr'acingthe rungsot the ladder and is of such form that it is readily manipulated, and is avery effective and strongvlock,

show the, operating trip device provided withtwo operating fingers ,for engagingthe lock successively. This makes a compact structure possible and avoids long, fragile parts."

I. Ifh ave shown, the parts made.,asflight, as

ure of the user.

possible, and. consequently have provided extra retainers for the partsso that they will remairr efiectively in position. These featl-lI-GSyhOWGYBI', can; be modified at the pleas- By'forniingqthe parts as indicated, illustrated and described; the. Parts are interchangeable, rights and lefts, for either side. Apairof locks is provided on each extension.

From, these statements, it will be- 0bserved that my improved structure is capable of flconsiderable modification without de-' partingcfrom my invention, which .is clearly defined and pointed out in the claims.

- Having thus described my invention, what Iclaim as newand desire tossecure by Letters Patent is; V a I I 1., Anextension ladder comprising'a lower section and an upper orextension section, consisting each of suitable side rails and rungs,suitable guides for retaining the ,ex-j tension section 1n place, a pivoted lock on the siderail; of the upper or extension sec ;tion,,, having a suitable, guide cross bar thereon, and downwardly-depending hook;

'pQrti h jtq-en aee: nd mapl the se together by embracing the adjacent rungs thereon',an enlarged head onthe hook that with one finger adaptedgto act upon the lock.

to swingthe same partially out of engage mam-with" the-main sectlon, andja second a short lever or guard that is entirely pro-"finger extending normally beyond the'side rail of the upper ;or;'extension 1 section to contact with thegrungs of' the lower section,

for throwing thelock into the disengaged position, disposedqto swinglandcoverpthe engaginghook to permit-the; extension sece g tionto. descendafter being raisedpast any particular rung, v coacting for the purpose 2. An extension ladder comprising a ldwer section and aniupper or j extension section, 11'. consisting each Of'SLl1l3Etbl6S1d6'rEL1lS' and havinga suitable guide cross bar thereon, j

and downwarly-depending hook portions to engage and couple the sections together by 1 embracing adjacent rungs thereof, an'enkg larged'head on the hook that embraces therung of the upper: orextension-3sectiony .a a

trip to act on said hea'd; ;to throw "said lock to; the inoperative; position,;;and guard finger to close over the said lock, as specified:

J 3. a In 1 an. extension ladder comprising .111):

per and lower sections, the combination of a hook lock on'th'e upp'er o'r extension. section, having a; plurality of, downwardlyap'roj ecting p I; arms that, act, automatically and successively a on therungs otthelower section,;' the upper arm of whichyhas anxenlargedzendg." and'a 1:

double actingtriprand "guard pivoted onksaid upper section} and having; a plurality of arms corresponding tothe, armsof the hook? V lock that: act on (said hookylockxarmsrsuca' cessively, the lower: of which arms extends 5.

the rungs; of the lower'ladder section andis 1 disposed to engage the lower armuofifthe. hook look after. it hasybeen moved bygthe-action of said trip'toguard' the sameandrper-ww imit; adjustment, as specified. 4.: In an extensionla'dder comprising. up per and lower sectio'ns,the combination of a V a hooklock on the upperior-e'xtensionsection, x having a plurality ofidownwardly-proj e'cting on the rungs of'the lower-section;aandsia double acting :trip" and guard'pivoted on said upper section and having plurality-' of arms, corresponding: to the arms: of the jhooki f i j lock that, act: on-saidcihookalock; armsi suc-j I cessively,;the. lower, of a which arms'fextends,

into and is disposed. in the path of travelzof arms that, act; automatically and successively into and isdisposed inithe path of travel of my hand and seal in the presence of two the rungs of the lowerladder section and is WltIlGSSBS. disposed to engagethe lower arm 0f :the hook lock after it has been moved by the ace tion of said "trip to guard the same and permit adjustment, as sfecified.

In Witness whereof, \have hereunto set ALLEN PJBOYER; [1 5.]

Witnesses: L. G. GREENFIELD,

MUL. GLASGOW.

Copies of this patentymay be obtained for fivecents each by addressing the Commissioner of Patents.

Washington, D; G. 

